I've owned 3 Subarus, all had the "All Weather Pkg" with the heating elements on the lower portion of the windshield...never helped with keeping the wipers from freezing up while the car was in motion.

Those front heating elements are only for freeing up the wipers when they are frozen to the windshield.

I had to reposition mine properly on both Subarus. Second, I ditched the OEM wipers for uniblade wipers similar to these because all the articulations of OEM styled wipers made them freeze.